Particularly in the pharmaceutical industry there is a necessity to identify pharmaceutical products uniquely based on information that is applied to the packaging. For this purpose relevant information is routinely printed on the front side of a packaging box. This information might include a product number, a lot number, an expiration date, and perhaps a number identifying the specific product. By recording the printed information and its evaluation, every individual package and therewith the product in it can be followed from the company manufacturing it via distribution channels to the end user. In this way counterfeit medicines can more easily be recognized and their use by the end user can be avoided.
Automatic information collection systems are known that can produce reproductions of the package area containing the information in order to evaluate the information on it. Such systems often comprise a camera or a different device to produce an image that produces a reproduction and transmits it to a suitable, often digital, evaluation device.
Increasingly, however, both individual folded boxes and in particular assembly packs that include several folded boxes are enclosed by a transparent film and where applicable combined into a unit and protected during transportation up to the sale to an end user. The package is not opaquely covered by the transparent film, often a cellophane film. The information printed on the package can be recognized and evaluated through the transparent film.
It has emerged, however, that the automatic recognition procedure known in past practice cannot reliably recognize and evaluate the information provided on the package if the area of the package showing the information is covered by cellophane. In the first place, undesirable mirroring and reflections occur that are caused by the encasing cellophane film or are at least distorted by it and which thereby hinder automatic evaluation by recording using a camera. In the second place the cellophane film is not always smooth on the surface of the package and may possibly have folds and waves that can produce additional reflections and distort an image of the area of the package under it.
Taking several pictures staggered in time of the area of the package showing the information is known, whereby the illumination is from various directions and the disturbing influence of distortion and reflections can be reduced by a comparison of several images. However, producing several camera images with differing illumination and the subsequent processing of images is wasteful, laborious and costly.
Illumination using polarized light on the package area showing the information and evaluation of the camera images produced with polarized light is also known. It has been shown, however, that in many cases the cellophane film can influence the polarization of the light so that the camera images produced with polarized light and in particular their evaluation may additionally be interfered with or altogether thwarted.